The Central Nervous System
The central nervous system has two divisions: the spinal cord, located in the vertebral cavity, and the brain, located in the brain cavity. The brain is enclosed within the skull and protected by fluid, which acts as a shock absorber. The central nervous system controls mental activity, and muscle and organ functioning. Its 100 billion plus neurons transmit and receive information to and from all parts of the body.
The human brain has evolved over millions of years and is the most complex organ known to man. Even to this day, scientists are still attempting to uncover all of its mysteries. This approximately two pound mass of gray matter, containing billions of nerve cells and located in the protective cranium, is responsible for controlling every organ and bodily function.
Chemicals of the Brain
The brain manufactures Chemicals, or hormones, called neurotransmitters that affect your physical health and influence moods and thought. Sixty neurotransmitters have been identified. Listed below are five that are commonly known and important in learning about anxiety:
Dopamine: regulates physical movement and emotion
Serotonin: affects mood and anxiety
Acetylcoline (Ach): controls attention, memory, and learning
Noradrenaline: produces physical and mental arousal and elevated mood
Glutamate: forms links between neurons that control learning and long-term memory
Endorphins: ease pain, reduce stress, and promote tranquility
Research indicates that neurotransmitters can be affected by what we do or think. For example, serotonin levels that affect anxiety may decrease because of chronic stress or increase due to feelings of happiness and a healthy lifestyle. These studies tell us that we are able to take charge of our emotions, and that anxiety does not have to rule our lives.
Parts of the Brain
The brain consists of three main parts:
Brain stem (reptilian brain): the medulla oblongata controls unconscious, automatic functions such as breathing, heartbeat, and blood pressure. Its cerebellum controls and regulates muscles, movement, and balance.
Midbrain: the thalamus relays information. The hypothalamus regulates drives and actions and is part of the limbic system, which is the center of emotions and drives.
Cerebrum: the largest and newest part of the brain on the evolutionary scale. It controls higher functions, such as thought, logic, language, voluntary muscle movement, decision making, and perception.
By studying the brain and its functions, it is understandable why the symptoms of anxiety shake up your system and make a powerful impact on your mind and body, from physiological processes, such as rapid heart rate, and trembling hands, to the inability to concentrate and memory loss.
The Spinal Cord
The spinal cord, a thin column of nerves, comprised of both sensory and motor neurons, is the main highway for sending and receiving information between the central nervous system (brain and spine), and the peripheral nervous system (sensory and motor neurons). The spinal column, which protects the spinal cord, is comprised of twenty-four small bones, with a gel-like disc between each vertebra that act as shock absorbers, and keep bones from rubbing against each other. Not only does the spinal cord allow you to control body movements, but without it, organs would not be able to function. When people have spinal cord injuries, depending on the severity of the injury and which vertebrae were damaged, they may not be able to walk and sometimes will require a respirator to breathe.